This invention relates generally to liquid tanks such as brake master cylinder reservoirs and more particularly to observing window devices usable on such tanks for visual confirmation of the liquid level in the tank from the outside thereof.
The present invention has for its object the provision of a novel observing window device of the kind concerned which is so designed that the transparent pane member thereof can be readily installed in a window opening formed in one of the side walls of a liquid tank in a leak-tight fashion and in such a manner as to be securely held against removal or dislocation by tampering from the tank outside.
Another object of the present invention is to provide an observing window device of the character described which is particularly simple in construction and enables level confirmation with ease and accuracy, including a combined light reflector and panel retainer plate arranged inside the liquid tank so as to securly hold the transparent pane member of the device in place in the window opening.
A further object of the present invention is to provide an observing window device of the character described which is of simple construction and in which the cover plate member of the liquid tank is utilized to firmly secure the transparent pane member in place in the window opening so as not to fall off the tank wall or be dislocated therein to allow fluid leakage even under severe vibration.
Yet another object of the present invention is to provide an observing window device of the character described in which the pane retainer plate is designed also to serve as a level indicator means for indicating the upper limit level of liquid in the liquid tank for convenience in replenishing the latter while serving as means for holding the pane member against rotation to keep a level mark thereon in its specified position.
These and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings.